To cite spatstat.Knet in publications use:

Rakshit S, Baddeley A, Nair G (2019). “Efficient Code for Second Order Analysis of Events on a Linear Network.” Journal of Statistical Software, 90(1), 1–37. doi:10.18637/jss.v090.i01.

Corresponding BibTeX entry:

  @Article{,
    title = {Efficient Code for Second Order Analysis of Events on a
      Linear Network},
    author = {Suman Rakshit and Adrian Baddeley and Gopalan Nair},
    journal = {Journal of Statistical Software},
    year = {2019},
    volume = {90},
    number = {1},
    pages = {1--37},
    doi = {10.18637/jss.v090.i01},
  }